Method for preparing fuel cell by taking metal organic framework material loaded with electron transfer mediator as anode modification material

Abstract

The invention relates to a method for preparing a fuel cell by taking an electron transfer mediator loaded metal organic framework material as an anode modification material. The metal organic framework material is a porous coordination high-molecular polymer crystal formed by coordination of metal ions and organic ligands. Many metal organic framework materials are poor in conductivity, and electron transfer and substance transfer between active sites of the metal organic framework materials and catalyzed reactants are difficult in the aspects of stereo, distance and the like. Through compounding of the metal organic framework material and the electron transfer mediator, electron transfer and substance transport capabilities between active sites of the metal organic framework material and a catalyzed reactant are enhanced, and the catalytic performance of the metal organic framework material can be greatly enhanced. The metal organic framework material loaded with the electron transfer mediator is used as an anode modification material, the metal organic framework material loaded with the electron transfer mediator is used as a catalyst, oxidation of target fuel is catalyzed, the fuel cell is constructed, and the method has the advantages of being easy to operate, simple in procedure and the like.

Description

Technical Field

[0001] The present invention relates to a fuel cell method, in particular to a fuel cell method for enhancing the electrocatalytic activity of anode materials of fuel cells. Background Art

[0002] Metal-organic frameworks (MOFs) are porous, coordinated polymer crystals composed of metal ions and organic ligands. Due to their numerous advantages, including large specific surface area, high porosity, adjustable pore structure, high catalytic activity, open metal active sites, and structural diversity, they have become a hot topic in the field of electrocatalytic materials research and development. However, many MOFs have poor electrical conductivity, and the electron transfer and mass transport between the active sites of many MOFs and the catalyzed reactants face difficulties in terms of steric and distance. By combining MOFs with other materials, the electron transfer and mass transport capabilities between the active sites of the MOFs and the catalyzed reactants can be enhanced, greatly enhancing the catalytic performance of the MOFs. The present invention uses a MOF material carrying an electron transfer mediator as an anode modification material and a MOF material carrying an electron transfer mediator as a catalyst to catalyze the oxidation of a target fuel and construct a fuel cell. Summary of the Invention

[0003] The present invention introduces an electron transfer mediator and establishes a fuel cell method using a metal organic framework material loaded with the electron transfer mediator as an anode modification material. The method has the advantages of easy operation and simple procedures.

[0004] Furthermore, the metal organic framework material loaded with an electron transfer mediator described in this patent is a composite material formed by the electron transfer mediator and the metal organic framework material, and the electron transfer mediator is loaded on the surface of the metal organic framework material or inside the pores of the metal organic framework material;

[0005] Furthermore, the metal-organic framework material loaded with an electron transfer mediator described in this patent refers to a material in which the electron transfer mediator and the metal-organic framework material are combined or connected with each other through covalency, adsorption, hydrogen bonding, hydrophilic interaction, hydrophobic interaction, or van der Waals force, or a combination of some or all of these interactions;

[0006] Furthermore, the metal-organic framework material carrying an electron transfer mediator described in this patent is modified at the anode substrate electrode interface of a fuel cell. Its activity in catalyzing the oxidation reaction of the fuel (reactant) in the fuel cell is higher than that of the metal-organic framework material used alone without the electron transfer mediator.

[0007] Furthermore, the electron transfer mediators described in this patent include, but are not limited to, ferrocene and its derivatives, tetrathiafulvalene and its derivatives, tetracyanoquinodimethane and its derivatives, various metal complexes with redox activity, various organic molecules with redox activity (including phenazine, phenothiazine, phenoxazine dye molecules, quinones, anthracenes), various high molecular polymers with redox activity, etc.;

[0008] Furthermore, the metal organic framework materials described in this patent are classified according to organic ligands, including but not limited to carboxylic acid, nitrogen heterocyclic and phosphonic acid metal organic framework materials, and mixtures of two or more thereof;

[0009] Furthermore, in the metal-organic framework materials described in this patent, the ligands of the carboxylic acid metal-organic framework materials include but are not limited to terephthalic acid, trimesic acid, etc.; the ligands of the nitrogen heterocyclic metal-organic framework materials include but are not limited to imidazole esters, bipyridine ligands, etc.;

[0010] Furthermore, the metal ions in the metal-organic framework materials described in this patent include, but are not limited to, positively charged ions of metals such as Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Zr in each effective valence state. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1. (a) Open-circuit voltage of glucose fuel cells using Cu-BTC / CC and TTF@Cu-BTC / CC as anodes; (b) Anodic polarization curves of glucose fuel cells using Cu-BTC / CC and TTF@Cu-BTC / CC as anodes. Electrolyte solution: 0.1 M NaOH. DETAILED DESCRIPTION

[0012] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0013] Materials, electrodes, and battery preparation

[0014] Dissolve 2 mmol of copper(II) acetate monohydrate in 20 mL of N,N'-dimethylformamide (DMF) and stir until completely dissolved, forming Solution A. Dissolve 1 mmol of the organic ligand 1,3,5-benzenetricarboxylic acid in 40 mL of DMF and allow to dissolve completely, forming Solution B. Pour Solution A into Solution B while stirring, stir for 15 minutes, and then pour the solution into an autoclave. The autoclave was placed in a 120°C oven for 24 hours, after which the temperature was automatically lowered. After the reaction system cooled to room temperature, the product was centrifuged and the solid was washed several times with ethanol. Finally, the product was dried in a 60°C oven under vacuum for 12 hours, then the solid was removed and ground to yield Cu-BTC.

[0015] Weigh 50 mg of the blue Cu-BTC solid prepared above and dissolve it in 10 mL of ethanol. Weigh 10 mg of tetrathiafulvalene (TTF), a brown solid, and dissolve it in 10 mL of ethanol, resulting in a yellow solution. Both solutions need to be ultrasonically treated to ensure uniform dispersion. After ultrasonication for 30 minutes, the two solutions are mixed and stirred continuously for 2 hours. After stirring, the mixture is allowed to stand for 12 hours to allow for further adsorption of TTF. After the standing time, the product is separated by centrifugation and the solid is washed several times with ethanol. The resulting solid is dried at room temperature (25°C) to obtain TTF@Cu-BTC.

[0016] The commercial carbon cloth (CC) was cut into a circle with a diameter of 0.7 cm and an area of ​​0.385 cm. 2 The CC was activated by soaking it in a mixed acid (HCl:H₂O:H₂SO₄) with a volume ratio of 1:3:2 for 30 minutes. Rinse thoroughly with water before use. A 10 mg / mL TTF@Cu-BTC ethanol dispersion was prepared and sonicated for 30 minutes to achieve uniform dispersion. 30 μL of the dispersion was then applied to the acidified CC and dried at room temperature. 5 μL of a 0.05 wt% Nafion solution was then added dropwise and dried at room temperature. Finally, a conductive silver wire was attached to the activated CC loaded with the material to obtain the TTF@Cu-BTC / CC anode. Cu-BTC / CC and TTF / CC were prepared using the same method. An anion exchange membrane (AEM) was placed in a 1.0 M NaOH aqueous solution at room temperature (25°C) for at least 24 hours. After rinsing with deionized water (pH ~7), it was ready for use. The TTF@Cu-BTC / CC electrode served as the anode, and the anion exchange membrane separated the middle of the two-chamber cell. The anode chamber contains 0.10 M NaOH solution containing glucose, and the cathode chamber contains a separate 0.10 M NaOH solution. The electrochemical workstation is connected to test the open circuit voltage and linear voltammetry curve ( Figure 1 ).

Claims

1. A fuel cell method using a metal organic framework material carrying an electron transfer mediator as an anode modification material, characterized in that: (1) The metal organic framework material carrying the electron transfer mediator is a composite material formed by the electron transfer mediator and the metal organic framework material, and the electron transfer mediator is loaded on the surface of the metal organic framework material or inside the pores of the metal organic framework material; (2) The metal organic framework material loaded with electron transfer mediators as mentioned in (1) refers to a material in which the electron transfer mediator and the metal organic framework material are combined or connected with each other through covalent action, adsorption, hydrogen bonding, hydrophilic interaction, hydrophobic interaction, or van der Waals force, or a combination of some or all of these effects; (3) The metal organic framework material carrying the electron transfer mediator described in (1) is modified on the anode substrate electrode interface of the fuel cell, and its activity in catalyzing the oxidation reaction of the reactant fuel of the fuel cell is higher than that of the metal organic framework material used alone without carrying the electron transfer mediator.

2. The method according to claim 1, characterized in that The electron transfer mediators include but are not limited to ferrocene and its derivatives, tetrathiafulvalene and its derivatives, tetracyanoquinodimethane and its derivatives, various metal complexes with redox activity, various organic molecules with redox activity, including phenazine, phenothiazine, phenoxazine dye molecules, quinones, anthracenes, various high molecular polymers with redox activity, etc.

3. The method according to claim 1, characterized in that The metal organic framework materials are classified according to organic ligands, including but not limited to carboxylic acid, nitrogen heterocyclic and phosphonic acid metal organic framework materials, and mixtures of two or more thereof.

4. The method according to claims 1 and 3, characterized in that Among the metal-organic framework materials, the ligands of the carboxylic acid metal-organic framework materials include but are not limited to terephthalic acid, trimesic acid, etc.; the ligands of the nitrogen heterocyclic metal-organic framework materials include but are not limited to imidazole esters, bipyridine ligands, etc.

5. The method according to claims 1 and 3, characterized in that The metal ions in the metal organic framework material include, but are not limited to, positively charged ions of metals such as Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Zr in each effective valence state.

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